I'm seeking some advice after taking my '49 F1 for it's first drive after 14 months of restoration work on Saturday. The problem I have is with the steering straight and going along at low speeds the truck wanders and needs constant correction. Below is a summary of the work done but I was hoping someone could answer a few questions I have.

- Steering box refurbish with new worm gear, supposedly adjusted correctly by the steering specialist.
- Drag link refurbish with new drag link kits from NPD
- New tie rod ends and center tie rod, seems to be tight at the joints from MACS
- King Pins have been replaced, had a couple of extra shims made up to make these tight.
- Wheel bearings have been replaced as part of the disc upgrade.
- New shock absorbers and top mounts

Therefore I think this leaves:
- Suspension shackles and bolts, I have the replacement bolts so I'll try and do those this weekend
- Excessive pitman arm wear, seemed not quite round but not too bad.
- Original ball joint at other end of drag link seemed fine, still round.
- Leaf springs themselves? Would these cause the issue?
- Bias ply tires, the G78-15 tires are old so I was thinking of replacing them?

Any advice would be greatly received. Thanks Richard.

Below are some of the photos during restoration:
Before:




Axle off to replace the King Pins and clean up:


Clean up:


Back in place with rebuild drag link:


Reassembled:

 

Go ahead and replace the shackle bolts and bushings. These being worn will allow the axle to shift. I've seen steering boxes rebuilt and adjusted too tight to where the vehicle won't self center the steering. Worn rear shackle bolts can cause a rear steer condition although not common.
Bias tires are not known for great handling steering characteristics. What is the caster setting? What is the toe setting?
Jack the truck and slowly turn the steering wheel lock to lock and feel for any tight action at center. Perhaps the steering expert adjusted the sector at other than "high point center".

 

I would definitly look at toe and caster also.

 

I agree shakel bolts, toe in, castor, and the only other thing I did was replace the pitman arm ball, and steering linkage ball. It sounds like your almost there, Id try toe in first its free and only takes a few minutes, then castor also free, and would only take shims if needed.

 

First thing, replace all 4 of the bias ply tires with radials. Bias ply, especially old ones are seldom round or run true. Belted bias ply belts shift, which just compounds the problem. Bias ply are notorious for tramlining, i.e. following the cracks and undulations in the roadway, get rid of them! Next replace the spring eye bushings and shackle pins front AND REAR. Once you have accomplished that, Jack up the driver's side of the front axle with the pass side tire still firmly on the ground. place two good sized C clamps on the frame trapping the pitman arm tightly between them so it cannot move. Try turning the steering wheel back and forth. If a point on the rim of the wheel moves more than an inch take the steering box back to the rebuilder and have him do it right. If the box is tight remove the clamps, and test again. If the freeplay at the wheel rim increases markedly, arm yourself with a strong light and enlist a helper. Crawl under the driver's side of the truck and have the helper turn the steering wheel back and forth just until the passenger wheel barely moves. As he/she is turning the wheel check every joint for any signs of freeplay, that is movement in that joint before the rest of the steering moves enough to begin turning the passenger wheel. Don't ever assume that a new part is a good part if you have freeplay. Why didn't you change the pitman arm ball if it showed any sign of wear? They should not show any visible wear, are cheap and easily replaced. If you are not comfortable changing the ball replace the pitman arm with a new/unworn one. Same with the one on the steering arm. Now if everything checks out or has been replaced, take the truck for a ride on it's new tires. If it still wanders increase the toe in 1/2 turn: back off the locking nuts on the tie rod ends at the tie rod 1 turn. (remember one is a right hand thread the other a left hand thread, if the nut doesn't loosen with a 12" open end, try turning it in the opposite direction) now turn the entire tie rod 1/2 turn in the direction that screws the tie rod ends further apart (increasing toe in, where the front of the tires are slightly closer together than the rear of the tires measured at 3 and 9 o"clock). Retighten the the locking nuts and do another test drive. You can do an advanced search on this forum for my post on DIY front end alignment, toe setting in the home shop. If the truck holds a straight line with your hands off the wheel most of the time (they will always slowly drift to the right due to the crown in the roadway), then we can check the caster. But if it still follows the cracks in the road, and/or wanders side to side put in an additional 1/2 turn of toe-in and test again. Unless the toe was way off 0 toe one way or the other adding 1 turn of toe in will not significantly increase tire wear or throw the handling off, but will tell you that was the problem if it improves. After the truck stops tramlining or is better after adding a maximum of 1 turn of toe in, we can test the caster setting. The factory caster is built into the spring perches but can decrease as the springs sag or if you remove leafs to soften/lower the ride or put in lowering springs. The original caster was meant for driving at less than 30 MPH with a full load in the bed on unpaved roads. Most of these old trucks can benefit from adding caster for driving on modern paved highways at today's highway speeds. If you are using stock spring stacks either OEM or stock replacement you can add caster by placing a tapered wedge between the spring and axle. Loosen the U bolts enough to slip the wedge into place and retighten being sure the spring eyebolt head indexes back into the recess in the spring pad. The wedge should be oriented so that top of the axle will lean back more increasing caster. Softened or lowering springs will likely take two sets of shims stacked to add additional caster. If stacking shims make sure the centerbolt head is still long enough to fully engage the hole in the axle. If not, Mid Fifty (and I'd assume Classic Haulers) sell longer headed center bolts. Search and read up on how to disassemble springs safely before attempting to change center bolts tho. Additional caster will also help correct any remaining tramlining and aid in returning the wheels to straight ahead after going around a corner.

 

The ball is not replaceable, a new pitman arm is the only option, and a $75 one. It won't do any good to replace it if you don't also replace the drag link innards, about $35.

PS Richard -- I'm curious how you shimmed the kingpins, can you give a little detail? Thanks

 

I was going to say something, but Ax said it all.

Does the truck ever shake when you hit a pothole or a bump?

 

Ross, in his first post he said he rebuilt the drag link. That why I questioned why he didn't change the ball since he said it "wasn't quite round". I didn't know the ball isn't replaceable, but I would have spent the 75.00 for the pitman at that point.

 

Bet it would feel like a different truck with new tires, even with the other possible/probably issues.

 

Thanks for all your detailed replies, much appreciated.


I should have mention that I believe the toe setting is correct and I had this checked at a local shop last weekend.



I think the next steps for this weekend are from the recommendations:
· - Replace the worn shackle bolts and bushes (I have these parts), although do the shackle normally wear or just the bolts and bushes.
· - Check the steering box for play with the C clamps method
· Replace the bias ply tires, currently bidding on some second hand tires and wheel on eBay. If this makes a difference I’ll look to purchase some new wheel and tires as my current wheels are in need of clean up and would be tempted to go back to steel wheels with chrome center caps.
· - Check the caster, I’ll post the results of this and obviously would appreciate your feedback. The axle/spring joint does have what I assume are the original wedges which slope the top of the axle backwards, i.e. the axle is higher at the front than at the back.
· - Replace the pitman arm. The reason I have not done this yet is I left it off my shopping list last trip. I and the truck live in the UK and it is not possible to obtain model specific parts here. Therefore when I come over to the US, usually twice a year, I stock up on parts and take them home in the checked luggage. Much cheaper than shipping which unfortunately makes a $75 pitman arm, $75 + plus USPS shipping $24 + $25 UK sales tax and duty (about 25% on item + shipping) + customs handling fee (£8 = $12) = $136, compared to $75 + $5.80 shipping if I hand carry it. Largest shopping trip 4 checked boxes/luggage totalling 210lb, and costing $150 in excess baggage.


Ross, on the king pins shims, I had to get the local bus company to help with this as whacking the old ones with a big hammer or 20t press was not shifting them. I’ll photograph the joint and add some detail at the weekend


51PanelMan, when you say shake. It does like to follow grooves/camber of the road and after hitting bumps in the road it wanders and needs correction. Also the suspension appears to bounce, making it a fight to correct it.


Thanks once again for all the advice.



Richard

 

Toe correct to what setting? OEM? Remember the stock spec was for a 60 year old vehicle driving on 60 year old tech post war truck tires, on mostly unpaved roads at low speed. Adding an additional 1/16 - 3/32" toe in and see how it reacts, it would only take a few minutes to adjust and return if it doesn't help. If you are buying used tires, take them to a tire (or is it tyre? ) shop and have them give them a good spin balance and check for cupping, flat spotting, run-out before putting them on the truck. Are new stock size radials that expensive there (you don't need HD 6 ply truck tires, standard sedan tires would be fine and give you better ride unless you are doing heavy duty hauling, driving off road)? I don't believe Ford ever used caster shims from the factory.

 

I should have asked what they set it to, but didn't unfortunately. After doing the other changes I'll try and set it again, is 1/8" toe-in what I should aim for?

Yep they are tyre shops other here.

You make a good point on the radials, maybe I should just put new on straight off. Although I would like to change the wheels out at some stage for steel wheels. The current wheels are G78-15, what radials would you go for?
215/75/15
225/70/15
235/70/15

All are about $140 a tire for new brand name tires. Although a whitewall version would be about $300 a tire.

Cheers

Richard

 

What width wheels are you using? What rear axle ratio do you have? What is your normal cruising speed? Suitable tires here would be in the 100- 150. USD each range, 300.00 would buy high end ultra performance sport tires. I'm not fond of WW myself, and would never pay double for them. Do you have some of the major asian tires available such as Kumho, Azeni, Toyo, Hankook, Yokohama, and how do the prices compare?

 

Ok, here's a bit of an update from the weekend:
- The toe in is 1/8" so I'll leave that for the moment.
- The castor, I struggled to measure accurately, is there a technique for doing this? This is a picture of the wedge that is currently between the leaf and axle. Larger part of the wedge towards the back of the truck.


Then I got to the shackle pins and bushing, or lack of. So far I have I have only managed to work on the drivers side, However on closer inspection the leaf appeared higher at the front than I thought it should be and I little bit off straight.


I was able to remove the pins that go through the eyes of the leaf spring.

Back bushing was worn, Pin ok but will replace both.


The front bushing and as a result the pin was it a very bad way.
Bushing alongside the new one.


Pin showing signs of excessive wear


So I removed the leaf spring and have replaced the bushings but I'm struggling to remove the front pin and bushings from the frame mount. This seems to be well and truly stuck. I have soaked it in WD40, whacked it hard with a heavy hammer, but no luck. I was planning to try two big G clamps with some thick steel between them applying pressure to the thread end of the pin and the clamp pressing against the frame. If anyone knows to a better technique, I'd appreciate the advice?

The shackles seem to be in OK condition so I'll probably leave those for now. Maybe pick up replacements next trip.

Thanks

Rich

 

Good pictures. Yes, it was time for a few new parts. While you have the springs out, make certain the center bolts are not sheared or partially sheared.